This doctoral thesis studies the revitalisation of Irish through language learning holidays in summer camps (called summer colleges) situated in officially Irish-speaking regions in the West of Ireland. In order to better understand the sociological impact of language teaching, previous work from two research traditions were mobilised: interactional linguistics applied to language teaching and critical sociolinguistics of language revitalisation movements. The importance of education for the legitimation of a language is widely acknowledged, however, few studies analyse the way pedagogical practices participate in defining the status of a language and the meaning attached to its learning. Therefore, the aim of this research is to explain how language learning holidays in summer colleges produce or question the social and spatial structure of bilingualism in Ireland. To do so, I produced a corpus of interactional data (class interactions and interviews), participant observations, questionnaires, and historical sources, through sociolinguistic fieldwork consisting of ethnographic case studies in three summer colleges. First, I show that Irish romantic-nationalists opened the first summer colleges at the beginning of the 20th century in order to produce the Gaeltacht, a space imagined as authentically Irish (and totally monolingual) which was supposed to serve as a model for the independence movement from the United Kingdom. Then, I explain how and why today, in the summer colleges I studied, the teaching of Irish is a way for organisers to carry out socio-economic and political projects at the local level. Firstly, language rules participate in the reproduction or the transformation of what I define (after Anderson 1991) as “the Gaeltacht imagined community”. Secondly, the pedagogical practices observed in two summer colleges lead students to appropriate the language differently: in the first course, Irish is constructed as a cultural object, whereas in the second one it is constructed as a linguistic resource in the plurilingual repertoire of students. Finally, I explore how the recent commodification of the teaching of Irish on the international tourism market unsettles the economy of linguistic resources. The main thesis is that the importance of language teaching institutions for language revitalisation lays in their capacities to produce “linguistic sociodysseys”, defined as narratives which justify specific social orders based on linguistic ideologies rationalized during the experience of learning.